TAC Tech => Mechanical => Topic started by: Mileswinger on November 06, 2021, 12:29:43 PM
-
Does anybody have know where the vacuum lines from the charcoal canister as well as the fuel pump go in trying to install a sniper efi and the wiring is easy but I’m not familiar with all of the vacuum lines and what I need to replace and hookup to the actual sniper unit
-
Wouldn't it be better to convert to an in-tank fuel pump system with a regulator? At that point you can just remove the charcoal canister.
-
I don't know if you have a purge valve of some sort or not on the sniper. The canister is very simple - the carburetor fuel bowl and the fuel tank were vented to it on the later cars. When the engine is running, you need a little air bleed sucking on it, and that's all you need. There was no control on it, no need for it. when you're driving, it sucks air through the carbon and eventually it dries out most of the gas that's stuck to the carbon. That's all it is.
If the sniper doesn't have some provision for "canister purge" specifically, then you could hook it to distributor vacuum advance and that work for the canister itself. That'll kill the advance signal, though, so don't do that if you are using a distributor with vacuum advance. If you don't have a good port for that, you could get some benefit by venting it inboard of the air filter. The air filter would have a little bit of pressure drop and that would make it pull a little bit.
I did some googling and I didn't find much. On the Dominator EFI, there was some discussion about creating a custom output, and using that output to turn on a solenoid valve in the purge line. If you can do that, you want to set it up so that it's only open above some non-idle RPM like maybe 1000 or 1500. That would then be able to run on manifold vacuum, which you hook as many things as you want to that.
-
I'm late to this thread, but I am running a Sniper Quadrajet EFI on my Olds 403 and I am not using the canister at all. Do you need to reinstall that for your emissions or just preference? I am also running the Holley in tank pump that does not require a return line - it returns in the tank itself. Happy to post photos or answer any questions - you may have this all worked out already.